Engine-starting apparatus



- 1,641,418 Sept. 6, 1927 w. ELSEY ENGINE S TRTING A PIPARATUS Filed May 6. 1925 Patented Sept. 6, 1927.

UNITED STATES GEORGE W. ELSEY, F ANDERSON, DELCO-REMY CORPORATION, 0F

PATENT OFFICE.

INDIANA, ASSIGNOR, .BY MESNE ASSIGNMENTSyTO DAYTON. OHIO, A CORPORATION lOlli DELAWARE.

Encima-STARTING APPARATUS.

Application filed Hay 6,' 1926. Serial N0. 107,109.

engine to be started. A It is among the objects of the invention to simplify the construction and reduce the cost y of manufacture of engine starting apparatus of the type referred to.

Further objects and advantages ofthe present invention will be apparent from the following description, reference belng had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: y.

Fig. 1 is a fragmentarv longitudinal sectional view of the engine starting apparatus embodying the present invention.

Fig. 2 is an end view of the clutch before .being assembled with ythe clutch drums.

i Fig. 3 is a fragmentary longitudinal sectional view of the clutch on a larger scale l than Fig. 1.

In the drawing, 20 designates the field 3 frame of an electriemotor which is controlled by a switch 21 mounted on the frame. and which includes an armature 22 rotatable upon a shaft 23. The shaft 23 is supported p by a bearing (not shown) attached vto ihe eld frame 20, and by bearings which are provided by a gear housing inember 26. The housing member 26 is provided with finished cylindrical sufaces 27 which are'adapted to be received y a cylindrical aperture within the frame of the engine (not shown) for'the purpose of supporting the gear housing'26.

The shaft23 is provided with splines 28 which are drivingly connected withthein- 45 ternally-splined hub 29l of a clutch drum 30 having a cylindrical'clutching surface 31 coaxial with the slightly tapered conical clutching surface 32 of a clutch drum 33 which is formed integrally with the hub 34 .of a pinion 35 which is movable endwisealong the shaft 23 into engagement with a gear 36 connected with the engine to be started. -The diameter of the left end of spring A surface' 32 is the same as the diameter of thc surface 31. The hub 29, is provided with an accurately-finished surface` 37 which has a running fit with a finished surface 38 provided on the interior of the clutch drum 33.

`W'hen these surfaces are engaged and the clutch drums abut, as shown in the drawing, the clutching surfaces 31 and 32 will be located in alignment so as to receive a clutch spring 39 having the internal periphery of its turns ground to substantiallv true cylin- -drical form and frictionally engageable with the clutch-drum surfaces 31 and 32.

The clutch members are maintained in assembledrelation by means including a tube 40 having portions 41 and 42 of different di- A ameters, thereby defininga shoulder 43. Be-

fore the portion 41 is provided with the annular groove 44 and the'inwardly-extendng ange 45, the clutch members are assembled within the tube 40 and are located so that a flange 46 provided by the clutch member 30 will abut the shoulder 43. The metal` is de formed to provide an annular bead 47 which engages the iange 46 in order that the clutch member 30 will be permanently assembled to the tube 40, the ange 46 being received by the groove 44 which is dened by the shoulder 43 andthe bead 47. The tube portion 41 is provided by a spinning operation with the flange which prevents separation of the clutch member 33 from the member 30 but relative to the memberv 30. The space between the spring 39 and the tube portion 41 may be packed with grease before the mem ber 33'is permanently assembled in position, in order to provide a supply of lubricant foi: the clutch which will be suilicient during the normal life of the clutch. The tube 41 therefore, acts as a lubricant housing and prevents the admission of dirt and other foreign substances to the clutch spring.

The clutch and pinion are moved endwise along the shaft 23 by means including'a 1ever 50 which is`pivotal1y mounted upon a rod 51 supported by the gear housing 26. The lower end of the lever is bifurcated t0 provide arms 52, each of which carries a stud or roller 53 received by the groove 54 which is defined by flanges 55 and 56 ofl a sleeve 57 slidable along the shaft 23. .Thee

sleeve 57 is attached by riveting or swedgermits the clutch member 33 to rotate freely ing at 58 to the inwardly-extending iange 70 which extends through a cup member 71 mounted upon the floor-board 72 of an automotive vehicle. The rod is provided with a.

pedal 73, and a spring 7 4 is located between the cup 71 and the pedal 73 for the purpose of maintaining the starting apparatus in the position shown in the drawing.

To start an engine with the apparatus described, the oedal 73 is pressed downwardly in order to cause the lever `50 to move in a counterclockwise direction and the clutch members and the pinion ,35 to move'toward the right in the drawing in order to mesh the pinion with an engine gear 36. During this movement of the lever 50 it will enga e the operating member 7 5 of the switch 21 1n order to close the switch and to cause the motor to crank the engine through the clutch and gearing described.

The clutch lspring 39 iscoiled in such a manner that when the shaft 28 is rotated in engine cranking direction the spring 39 will contract toincreasethe frictional gripabout the clutch drums in order to transmit the torque required to crank the engine. The

spring 39 is initiallyr cylindrically-helical, audits internal diameter is slightly less than the diameter of the drum surface 31. When the spring is assembled upon the clutch drums it will en age the drum surface 31 with relatively slight unit pressure, but the conical drum surface 32 will be engaged by the spring with greater unit'pressure. than exerted upon the surface 31. rlhis effect is due to the fact that the width of the surface of contact of each spring coil engaging the drum surface 31 is the Width of the cylindrically-helical lsurface with which the spring is initially provided, whereas the width of the surface of contact of each spring coil engaging'the conical drum sur-i face 32 is much narrower than the width of each coil--theoretically a helical line contact. Furthermore, the total pressurel normally exerted by lthe coils embracing the conical surface 32 is greater than thetotal I pressure exerted by the coils embracing the' surface 31, since the former coils are wedgingly engaged by the conical surface 32 and are therefore expanded by the surface 32 in creasingly'proceeding toward the righthand end of the spring, as viewed in the drawing.

- gine becomes self-operative.

The right end turn of the spring` 39 will exert tie greatest-pressure since itis ex-. panded to the greatest devree. l When the shaftv 28.beg1ns to turn in the engine cranking direction, the spring coils embracing the drum 30 lwill be frictionally dragged ahead of the coils embracing the drum 33, since the pinion 35 is held stationary by the engine gear 36` and the spring coils embracing the drum 33 tend to remain -76 stationary due 4.to the relatively great lfriesl tion betweenthese coils and the drum33.- Engine cranking rotation of `the shaft 28 tends to wind up the spring 39 and to 'cause it to contract about the clutch drums'to the 80 extent that the pressure between the spring and the drums is sufficient to transmit the torque required to crank the engine. When the engine becomes self-o rative, it

will rotate the clutch member 33t roughthe 35 gearing 36 and 35 at a speedy greater than the motor will rotate it. The spring coils embracing the drum 33 will be dragged ahead of the spring coilsv embracing the drum30,

and the spring will be unwound and expandl ed in order to reduce the pressure exerted by the spring upon the drum 30 sufficiently to permit the spring to overrun the drum 30. Thus the pinion 35 will freelyl overrun the y motor shaft 23 and the'motor will not be 95. rotated at an excessive speed after the en- 'llhe coils which embrace. the drum 30,are

required to grip drivingly and to overrun the f-.

drum 30. The total initial pressure must 300 not be so great asito prevent overrunning, yet this pressuremust be increased sufficient-- ly to transmit cranking torque. These'condi -tions require the use of a certain number of turns of the spring to engage -the drum 30.

The turns embracino` drum 33 are not required to-overrun said rum but only frictionally-to grip it with pressure which is initial`v ly sufficient to Aanchor one end of thev spring to the drum 33, and withl pressure is iin'ally U0- suiicient to transmit cranking .torque. Therefore the number of spring turns required to engage the drum 33 may be less than the number ofl turns required to engage the drum30f,-' because the totals ring pres- 'N5 sure exerted by the spring upon t ie drum 33- 1s subject to lessvariation than the total spring pressure 'exerted by the spring upolL the drum 30. Another reason why the number of turns embracing the drum 33 can be 129 yless than the `number' of, turns embracing the drum 30 is because the coefficient of friction between the turns embrac'ng the drum V33 vis greater than the coeflicie t of friction between the turns embracing the drum-30. m5

In order that the clutch may overrun, the

surface31'must be lubricated. This ,can-v t notbe done practically without also lubrieating the surface 32. Since the unit pressure exerted by those coils embracing the Wl` surface 32 is greater than the unit pressure exerted by those coils embracing the surface 31, there will be less lubricant between the surface 32 and the spring than between the surface 31 and the spring. Hence the coefficient of friction between the spring and surface 32 will be greater than between the spring and surface 31, particularly since the oil film between the spring and surface 82 may be destroyed.

The result of this construction and ar rangement is that the clutch may be made shorter and with less material than a spring clutch having both clutch drums cylindrical. ft is of course obvious that the drums could be reversed. For example, the cylindrical drum could be attached to thev pinion, and the conical di'uin could be splined to the motor shaft.

Motion is transmitted yieldingly from the lever 50 to the clutch member 3() by the spring 63 so that the motor switch 21 may,

be closed prior to meshing the pinion 35 with the engine gear 36 in case the pinion teeth abut the engine gear teeth before the pinion is ineshed.

After the engine becomes self-operative, `the operator may release the pedal 7 3 whereupon the spring 7 4 will cause the lever 50 to move clockwise into the position shown in the drawing. The pinion 35 will be withdrawn from engagement with the engine gear 36 by a non-yielding device which includes the tubular parts 42 and 60 which cooperate through the engagement of their respective flanges 62 and 61. V

The clutch spring 39 may be caused to grip the clutch drum 30 sooner if its end portion 39b is bent slightly inwardly from the inner periphery of the clutch spring as shown in Fig. 2. Y

While the form of embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

lVhat is claimed is as follows:

1. Engine starting apparatus comprising, in combination, a motor, a shaft operated by the motor, a clutch member drivingly connected with the shaft and slidable along the shaft, a clutch member slidable along the shaft and rotatable independently thereof, said clutch members having coaxial friction surfaces, a helical-coil spring adapted to frictionallyl engage said surfaces and to provide a one-way driving connection between said members, a pinion slidable along the shaft and connected with the second clutch member, a tubular member enclosing the clutch members and preventing separation of the clutch members while permitting relative rotation of said members, means for yieldingly moving the clutch members and pinion in a direction to mesh the pinion with an engine gear and including a sleeve slidable along the shaft and a spring surrounding the shaft and located between the sleeve and first clutch member, and means for nonieldingly withdrawing the pinion from t e engine gear and including said sleeve and two telescopically coacting tubular parts enclosing the second mentioned spring, one part being attached to said sleevey and the other being an extension of said tubular member, said tubular parts having coacting fianges limiting separation of said sleeve from said clutch members.

2. Engine starting apparatus according to claim 1, and in which the clutch members are provided with external, coaxial friction sur- /faces which are engaged by a clutch spring which surrounds said surfaces, and the tubular member cooperates:I with outwardly extending annular flanges provided respectively by said clutch members and including said clutch spring.

3. Engine starting apparatus according to claim 1, and in which; the clutch members are provided with external, coaxial friction surfaces which are engaged by a clutch spring which surrounds said surfaces, and

the first mentioned clutch member is provided with an outwardly extending annular vflange which is received by a groove in the tubular member intermediate the ends thereof.

4. Engine starting apparatus according to claim 1, and in which the clutch members are provided with external, coaxial friction surfaces which are engaged by a clutch spring which surrounds said surfaces, and the tubular member is connected intermediate its lends with the first mentioned clutch member and is provided with an inwardly extending annular flange at each end, one

fiange cooperating with the second men-y tioned clutch member to prevent separation thereof from the first clutch member, and the other fiange cooperating with an outwardly extending annular flange provided at one end of the tubular part which is attached to the slidable sleeve and which is telescopically received by said tubular member.

5. .Engine starting apparatus comprising, in combination, a motor, a shaft operated by the motor, a pinion adapted to engage a gear connected with the engine to be started, and a one-way clutch vfor connecting the shaft with the pinion and including abutting coaxial friction clutch drums, one having a cylindrical surface and the other a conical surface, abutting edges of said drumv surfaces 'being substantially the same in dialneter, and a coiled, spring normally in frictional l engagement with the -drums and wedgingly engagedby the conical surface,l said spring being free of positive connection with the' drum.

6. Engine starting apparatus such as delined by claim 5 in Whlch the width of surface of contact between the sprin and the conical surface is less than the wi th of the surface of contact between the spring and the cylindrical surface, for the purpose specified. p

7. Engine starting apparatus -such as defined by claim 5 in which the spring is provided initially with a clutch drum engaging surface which 4is cylindrically helical and of substantial width, the surface of the spring which is Wedgingly engaged by the conical surface being less in width vthan the width of said c'ylindrically-helical clutch drum engaging 'surface of the spring.'

8. Engine starting apparatus such as defined by claim 5 .having 'the clutch drums provided externally with abutting cylindrical and conical surfaces respectively, the diameter of the conical surface'increasing from that of the cylindrical surface, and a sin le, initially cylindrically-helical` spiraly sprmg` in frictional engagement with the drums.

9. Engine startlng apparatus comprising in combination, a motor, asshaft driven-b the motor, a pinion slidable alongthe sha into engagement with the gear of an engine to be staijted, a one-way clutch having its driving member splinedly connected with the shaft and its driven member connected with the pinion, a manually operable member, a sleeve movable along the shaft and actuated by said member, a spring surrounding the shaft and located between the sleeve and clutch for transmitting motion from the sleeve to the clutch, and means surrounding the spring for limiting separation of the sleeve from the clutch While permitting the sleeve to approach the clutch.

10. Engine starting apparatus according to claim ll0 in which the means limiting the separation of the sleeve from the clutch comprises telescopically engaging tubes surrounding the spring and attached respectively to the sleeve and clutch, the normally adjacent end portions of the tubes having cooperating flanges to limit separation of the tubes while ermitting the sleeve to approach the clutcli.`

InlI testimony whereof I hereto affix my signature.

GEORGE W. ELSEY. 

